The present invention relates to reticle designs for C-arm surgical image intensifiers.
The present invention provides reticle systems for attachment to an image intensifier and methods of use which allow a standard C-arm image intensifier to be easily aligned to rotate in a selected plane about any desired point in a human body. The present invention can be used to align an image intensifier to rotate in any plane through the human body, wherein the plane is preferably defined by viewing bones or other radio-opaque structures in the body with the image intensifier system. Although the present invention can be aligned to rotate the C-arm in any desired plane passing through a human body, the present invention is ideally suited to align a conventional C-arm image intensifier to rotate in a plane passing between two adjacent vertebrae in a patient""s spine. It is to be understood, however, that the present invention is not so limited to alignment of C-arm image intensifiers only with respect to intervertebral planes.
After aligning the orientation of the image intensifier with the selected intervertebral plane, the image intensifier can be rotated about a selected point to provide both lateral and anterior-posterior views through the patient while remaining in the selected intervertebral plane.
The present invention also provides an improved reticle having indicia which can be easily aligned with opposing vertebral end plates such that the reticle can be used to align a C-arm image intensifier with a patient""s intervertebral plane.
In accordance with an aspect of the present invention, a surgical instrument can be advanced into the patient such that it passes between a pair of parallel indicia lines, with the instrument being guided along a preferred plane into the patient.
In accordance with another aspect of the invention, the present reticle provides indicia which do not cross over one another at the center of the reticle. An advantage of such a design is that the surgeons"" view is not obstructed at the operative site by any line or cross hair passing over the center of the reticle.